1. Field of the Invention
Embodiments of the present invention, as discussed herein, relate to image data encoding, and more particularly, to a method, medium, and apparatus controlling a bit rate in image data encoding to encode image data of a frame according to a predetermined bit rate.
2. Description of the Related Art
When image data is conventionally encoded, a frame unit is divided into blocks of a predetermined size and the blocks are transformed and quantized to produce a bitstream. To adjust the amount of bits of the bitstream for the blocks, a bit rate is controlled.
However, when image data is conventionally encoded, it is difficult to accurately produce a bitstream for each frame. In other words, under buffer-constrained bit rate control, rough bit rate control is possible, while accurate bit rate control is difficult.
Because of the difficulties of accurate bit rate control, the amount of bits stored in a buffer that temporarily stores an encoded bitstream significantly changes according to image data and a garbage bit is frequently inserted to maintain the amount of bits output from the buffer and transmitted to a memory constant, and in effect, precluding the buffer from efficiently performing its function.